{They watched} (paret(8872)oun). Imperfect tense, were watching
on the side (or sly). Luke uses the middle voice, paret(8872)ounto,
to accent their personal interest in the proceedings. It was the
sabbath day and in the synagogue and they were there ready to
catch him in the act if he should dare to violate their rules as
he had done in the wheat fields on the previous sabbath. Probably
the same Pharisees are present now as then. {That they might
accuse him} (hina kat(8867)or(8873)(9373)in autou). So  Mt 12:10 . Luke has
it "that they might find how to accuse him" (hina heur(9373)in
kat(8867)orein autou). They were determined to accuse him. The
sabbath controversy offered the best opening. So here they are
ready for business.